Refrigerator

ABSTRACT

According to an aspect of the present invention, there is provided a refrigerator including a cabinet in which a storage compartment is formed; a refrigerator door for opening and closing the storage compartment; a door opening device having a push rod which may move from an initial position to a door opening position for opening the refrigerator door and a motor for providing power to the push rod; and a controller controlling the motor, wherein the controller controls the push rod to move to the door opening position while in close contact with the cabinet or the refrigerator door in order to open the refrigerator door, and controls voltage supply to the motor so that a time period when the push rod is moved to the door opening position is maintained for a certain time.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/570,873, filed on Oct. 31, 2017, now allowed, which is the U.S.National Phase Application under 35 U.S.C. § 371 of InternationalApplication PCT/KR2016/008417, filed on Jul. 29, 2016, which claims thebenefit of Korean Application No. 10-2015-0108162, filed on Jul. 30,2015, and Korean Application No. 10-2015-0108163, filed on Jul. 30,2015, the entire contents of which are hereby incorporated by referencein their entireties.

TECHNICAL FIELD

A refrigerator is disclosed herein.

BACKGROUND ART

In general, a refrigerator is a home electric appliance for keeping foodand drink at a low temperature in an inner storage compartment shieldedby a door.

A method for opening a refrigerator door has been disclosed in KoreanPatent Application Publication No. 2011-0040030 (Publication Date: Apr.20, 2011).

In the publication, a door handle is provided at the refrigerator doorand a manipulation unit is provided at the door handle. And, a dooropening device is provided at a cabinet forming a storage space. When auser operates the manipulation unit, a push rod configuring the dooropening device pushes and opens the refrigerator door.

The push rod receives a driving force generated from a driving motor bya plurality of gears and performs a linear motion.

The push rod moves forward and may move to a set position for openingthe door. And, in the case in which a position detecting member detectsthat the push rod moves to the set position, the driving motor isrotated reversely and the push rod is returned to its initial position.

According to the prior art document, since the driving motor constantlyoperates until the push rod moves to the set position, in the case inwhich an external force is applied to the refrigerator door in theprocess that the driving motor is operating, there is a problem that thepush rod and the gears are broken or the driving motor is damaged due tooverload of the driving motor.

Also, since the driving motor is constantly operating until the push rodmoves to the set position regardless of the door opening by the userwhen the push rod is moving, in the case in which the user closes thedoor after increasing an opening angle of the door in the process of thepush rod moving forward to the set position, a rotational force forclosing the door is transmitted to the plurality of gears through thepush rod, and thus there is a problem that the push rod and/or the gearare damaged.

DISCLOSURE Technical Problem

The present invention is directed to providing a refrigerator in which apush rod and/or a gear for transmitting power to the push rod isprevented from being damaged by an action of an external load while thepush rod for opening a door moves to a door opening position or whilethe push rod is moved to the door opening position, and a control methodof the same.

The present invention is also directed to providing a refrigerator inwhich a door opening state may be maintained in a certain time while apush rod is moved to a door opening position, and a control method ofthe same.

The present invention is also directed to providing a refrigerator inwhich a door is prevented from being rattled in the process of openingthe door, and a control method of the same.

The present invention is also directed to providing a refrigerator inwhich a push rod and/or a gear for transmitting power to the push rod isprevented from being damaged due to a door closed by a user while thepush rod for opening the door moves to a door opening position or beforethe push rod returns to an initial position after moving to the dooropening position, and a control method of the same.

Technical Solution

According to an aspect of the present invention, there is provided arefrigerator including a cabinet in which a storage compartment isformed; a refrigerator door for opening and closing the storagecompartment; a door opening device having a push rod which may move froman initial position to a door opening position for opening therefrigerator door and a motor for providing power to the push rod; and acontroller controlling the motor, wherein the controller controls thepush rod to move to the door opening position while in close contactwith the cabinet or the refrigerator door in order to open therefrigerator door, and controls voltage supply to the motor so that atime period in which the push rod is moved to the door opening positionis maintained for a certain time.

The push rod may include an arc-shaped rack gear which may receive powerof the motor.

The controller may supply a voltage to the motor so that the motor isrotated in a first direction in order to move the push rod from theinitial position to the door opening position.

The controller may control the motor so that a rotational speed of themotor is reduced in the process that the push rod moves from the initialposition to the door opening position.

The controller may control the motor so that the motor rotates in afirst rotational speed and may control the motor so that the rotationalspeed of the motor becomes a second rotational speed which is lower thanthe first rotational speed at a certain point of time.

When the rotational speed of the motor reaches to the second rotationalspeed, the controller may control the motor so that the rotational speedof the motor is maintained in the second rotational speed until the pushrod reaches to the door opening position.

The refrigerator may further include a motor rotation detecting portionfor detecting the rotation of the motor, wherein the motor rotationdetecting portion may output a pulse in the rotation process of themotor, and the certain point of time may be a point of time when thenumber of pulses output from the motor rotation detecting portionreaches to a first reference number.

The speed of the motor at a point of time when the number of the pulsesoutput from the motor rotation detecting portion reaches to a secondreference number which is larger than the first reference number may bethe second rotational speed.

The refrigerator may further include a motor rotation detecting portionfor detecting the rotation of the motor, wherein while the motor isrotated in one direction for opening the refrigerator door and the pushrod moves from the initial position to the door opening position, thecontroller may determine whether an external load is acting on therefrigerator door in a direction in which the refrigerator door isclosed based on information detected from the motor rotation detectingportion.

When it is determined that the external load acts on the refrigeratordoor, the motor may be rotated in the other direction so that the pushrod returns to the initial position.

The motor rotation detecting portion may output a pulse in the rotationprocess of the motor, and in the case in which the number of pulses tobe output per unit time in the motor rotation detecting portion is equalto or less than the number of detected loads, the controller may rotatethe motor in the other direction so that the push rod returns to theinitial position.

When the push rod reaches to the door opening position, the controllermay stop the motor, and while the push rod reaches to the door openingposition, the controller may determine whether the external load acts onthe refrigerator door in the direction in which the refrigerator door isclosed based on the information detected from the motor rotationdetecting portion.

When it is determined that the external load acts on the refrigeratordoor, the motor may be rotated in the other direction so that the pushrod returns to the initial position.

The controller may stop the motor when the push rod moves to the dooropening position, and may supply a voltage to the motor so that the pushrod is maintained in a suspended state at the door opening position.

The refrigerator may further include a motor rotation detecting portiondetecting the rotation of the motor, wherein when the motor is rotated,a pulse may be output from the motor rotation detecting portion, and thecontroller may control a period of the voltage supplied to the motorsuch that the pulse is not output from the motor rotation detectingportion.

When a certain time elapses from a point of time when the rotation ofthe motor is stopped, the controller may rotate the motor in the otherdirection so that the push rod returns from the door opening position tothe initial position.

The refrigerator may further include a door opening detecting portionfor detecting whether the refrigerator door is opened at equal to ormore than a reference angle, wherein when the door opening detectingportion detects that the refrigerator door is opened at equal to or morethan the reference angle before the push rod returns to the initialposition, the controller may control the motor so that the push rodreturns to the initial position.

The refrigerator door may include a first refrigerator door and a secondrefrigerator door deposed in a right and left direction. While the pushrod is moved to the door opening position, at least a portion of a rearsurface of an opened refrigerator door of the first refrigerator doorand the second refrigerator door may be positioned forward than a frontsurface of a closed refrigerator door of the first refrigerator door andthe second refrigerator door.

According to another aspect of the present invention, there is provideda refrigerator including a cabinet in which a storage compartment isformed; a refrigerator door for opening and closing the storagecompartment; a door opening device having a push rod which may move froman initial position to a door opening position for opening therefrigerator door and a motor for providing power to the push rod; and acontroller controlling the motor, wherein the controller controls themotor so that a rotational speed of the motor is reduced in the processthat the push rod moves from the initial position to the door openingposition in order to open the refrigerator door.

The controller may control the motor so that the motor rotates in afirst rotational speed and may control the motor so that the rotationalspeed of the motor becomes a second rotational speed lower than thefirst rotational speed at a certain point of time.

The controller may control the motor so that the rotational speed of themotor is linearly or non-linearly reduced from the first rotationalspeed to the second rotational speed.

When the rotational speed of the motor reaches to the second rotationalspeed, the controller may control the motor so that the rotational speedof the motor is maintained in the second rotational speed until the pushrod reaches to the door opening position.

The refrigerator may further include a motor rotation detecting portionfor detecting the rotation of the motor.

The motor rotation detecting portion outputs a pulse in the rotationprocess of the motor, and the certain point of time may be a point oftime when the number of the pulses output from the motor rotationdetecting portion reaches to a first reference number.

The speed of the motor at a point of time when the number of the pulsesoutput from the motor rotation detecting portion reaches to a secondreference number which is larger than the first reference number is thesecond rotational speed.

The refrigerator may further include a motor rotation detecting portionfor detecting the rotation of the motor.

While the motor operates in one direction for opening the refrigeratordoor and the push rod moves to the door opening position from theinitial position, the controller may determine whether an external loadis acting on the refrigerator door in a direction in which therefrigerator door is closed based on information detected from the motorrotation detecting portion.

When it is determined that the external load acts on the refrigeratordoor, the controller may rotate the motor in the other direction so thatthe push rod returns to the initial position.

The motor rotation detecting portion may output the pulse in therotation process of the motor, and in the case in which the number ofpulses output per unit time in the motor rotation detecting portion isequal to or less than the number of detected loads, the controller mayrotate the motor in the other direction so that the push rod returns tothe initial position.

The controller may determine whether the external load acts on therefrigerator door after the motor is rotated in one direction and areference time elapses.

The controller may stop the motor when the push rod reaches to the dooropening position.

While the push rod reaches to the door opening position, the controllermay determine whether the external load acts on the refrigerator door inthe direction in which the refrigerator door is closed based on theinformation detected from the motor rotation detecting portion.

When it is determined that the external load acts on the refrigeratordoor, the motor may be rotated in the other direction so that the pushrod returns to the initial position.

According to still another aspect of the present invention, there isprovided a refrigerator including a cabinet in which a storagecompartment is formed; a refrigerator door for opening and closing thestorage compartment; a door opening device having a push rod which maymove from an initial position to a door opening position for opening therefrigerator door and a motor for providing power to the push rod; amotor rotation detecting portion for detecting rotation of the motor;and a controller controlling the motor.

While the motor operates in one direction for opening the refrigeratordoor and the push rod moves to the door opening position from theinitial position, the controller may determine whether an external loadis acting on the refrigerator door in a direction in which therefrigerator door is closed based on information detected from the motorrotation detecting portion.

When it is determined that the external load acts on the refrigeratordoor, the motor may be rotated in the other direction so that the pushrod returns to the initial position.

The motor rotation detecting portion may output a pulse in the rotationprocess of the motor, and in the case in which the number of pulsesoutput per unit time in the motor rotation detecting portion is equal toor less than the number of detected loads, the controller may rotate themotor in the other direction so that the push rod returns to the initialposition.

The controller may determine whether the external load acts on therefrigerator door after the motor is rotated in one direction and areference time elapses.

When the push rod reaches to the door opening position, the controllermay stop the motor, and while the push rod reaches to the door openingposition, the controller may determine whether the external load acts onthe refrigerator door in the direction in which the refrigerator door isclosed based on the information detected from the motor rotationdetecting portion.

When it is determined that the external load acts on the refrigeratordoor, the controller may rotate the motor in the other direction so thatthe push rod returns to the initial position.

The motor rotation detecting portion may output the pulse in therotation process of the motor, and in the case in which the number ofpulses output per unit time in the motor rotation detecting portion isequal to or more than the number of detected loads, the controller mayrotate the motor in the other direction so that the push rod returns tothe initial position.

According to yet another aspect of the present invention, there isprovided a refrigerator including a cabinet in which a storagecompartment is formed; a refrigerator door for opening and closing thestorage compartment; a door opening device having a push rod which maymove from an initial position to a door opening position for opening therefrigerator door and a motor for providing power to the push rod; and acontroller controlling the motor, wherein the controller rotates themotor in one direction so that the push rod moves from the initialposition to the door opening position in order to open the refrigeratordoor.

When the push rod reaches to the door opening position, the controllermay stop the rotation of the motor and may supply a voltage to the motorso that the motor is prevented from being rotated in the otherdirection.

The refrigerator may further include a motor rotation detecting portiondetecting the rotation of the motor, wherein when the motor is rotated,a pulse is output from the motor rotation detecting portion, and thecontroller may control a period of the voltage supplied to the motorsuch that the pulse is not output from the motor rotation detectingportion.

When a certain time elapses from a time when the rotation of the motoris stopped, the controller may rotate the motor in the other directionso that the push rod returns from the door opening position to theinitial position.

According to yet another aspect of the present invention, there isprovided a refrigerator including a cabinet in which a storagecompartment is formed; a refrigerator door for opening and closing thestorage compartment; a door opening device having a push rod which maymove between an initial position and a door opening position for openingand closing the refrigerator door and a motor for providing power to thepush rod; a door opening detecting portion for detecting whether thedoor is opened at equal to or more than a reference angle; and acontroller controlling the motor based on information detected from thedoor opening detecting portion.

When the door opening detecting portion detects that the refrigeratordoor is opened at equal to or more than the reference angle before thepush rod returns to the initial position, the controller may control themotor so that the push rod returns to the initial position.

The reference angle may be larger than an opening angle of therefrigerator door while the push rod moves to the door opening position.

When the door opening detecting portion detects that the refrigeratordoor is opened at equal to or more than the reference angle while thepush rod moves from the initial position to the door opening position,the controller may control the motor so that the push rod returns to theinitial position.

When the push rod reaches to the door opening position, the motor may bestopped, and when a certain time elapses while the push rod is moved tothe door opening position and the motor is stopped, the controller maycontrol the motor so that the push rod returns from the door openingposition to the initial position.

When the door opening detecting portion detects that the refrigeratordoor is opened at equal to or more than the reference angle before thecertain time elapses while the push rod is moved to the door openingposition and the motor is stopped, the controller may control the motorso that the push rod returns to the initial position.

The refrigerator may further include a hinge assembly having a hingeshaft for connecting the cabinet and the refrigerator door, wherein thedoor opening detecting portion may include a sensor outputting a signaland located adjacent to the hinge shaft.

The door opening detecting portion may further include a magnet providedin any one of the hinge assembly and the refrigerator door. The sensormay be a magnetic sensor detecting a magnetic of the magnet, and may beprovided in the other one of the hinge assembly and the refrigeratordoor.

The door opening detecting portion may further include a magnet providedin any one of the hinge assembly and the refrigerator door.

The sensor may be a magnet sensor which is turned on by magnet when therefrigerator door is opened at less than the reference angle and whichis turned off when the refrigerator door is opened at equal to or morethan the reference angle, and may be provided in the other one of thehinge assembly and the refrigerator door.

The sensor may be a micro switch provided in any one of the hingeassembly and the refrigerator door.

The door opening detecting portion may further include a switch controlportion provided in the other one of the hinge assembly and therefrigerator door and turning on the micro switch when the refrigeratordoor is opened by the reference angle.

The sensor may include a light emitting portion and a light receivingportion, and when the refrigerator door rotates at the reference angle,light irradiated from the light emitting portion reaches to the lightreceiving portion, and when the light reaches to the light receivingportion, the controller may determine that the refrigerator door isopened by the reference angle.

The light emitting portion and the light receiving portion may bedisposed in any one of the refrigerator door and the hinge assembly.

The light emitting portion may be disposed in any one of therefrigerator door and the hinge assembly, and the light receivingportion may be disposed in the other one of the refrigerator door andthe hinge assembly.

According to yet another aspect of the present invention, there isprovided a control method of a refrigerator including a step in which amotor operates in one direction and a push rod moves from an initialposition to a door opening position for opening a refrigerator door; anda step in which whether a certain time elapses after the push rodreaches to the door opening position is determined; and a step in which,when it is determined that the certain time elapses, the motor operatesin the other direction so that the push rod returns to the initialposition.

The rotational speed of the motor may be controlled so that a onedirectional rotational speed of the motor is reduced in the process thatthe push rod moves from the initial position to the door openingposition.

The rotational speed of the motor may be controlled so that the onedirectional rotational speed of the motor is reduced for a certain timeuntil when the speed is maintained at a first rotational speed andreaches to a second rotational speed which is lower than the firstrotational speed.

A step to move from the initial position to the door opening positionmay include a step in which the controller determines whether anexternal load acts on the refrigerator door in a direction in which therefrigerator door is closed, and a step in which, when it is determinedthat the external load acts on the refrigerator door, the controllerrotates the motor in the other direction so that the push rod returns tothe initial position even before reaching to the door opening position.

When the push rod reaches to the door opening position, the controllermay supply a voltage to the motor so that the rotation of the motor inthe other direction is prevented.

In the case in which the push rod reaches to the door opening position,the controller may determine whether the external load acts on therefrigerator door in the direction in which the refrigerator door isclosed, and when it is determined that the external load acts on therefrigerator door, the controller may rotate the motor in the otherdirection so that the push rod returns to the initial position.

According to yet another aspect of the present invention, there isprovided a control method of a refrigerator including a step in which apush rod moves from an initial position to a door opening position by anoperation of a motor for opening a refrigerator door; a step in which acontroller determines whether the opening of the refrigerator door isdetected at a door opening detecting portion before the push rod reachesfrom the initial position to the door opening position; and a step inwhich the controller controls the motor based on whether the opening ofthe refrigerator door is detected at the door opening detecting portion.

A step in which the controller controls the motor may include a step inwhich the controller controls the motor so that the push rod returns tothe initial position when the door opening detecting portion determinesthat the refrigerator door is opened before the push rod reaches to thedoor opening position.

A step in which the controller controls the motor may include a step inwhich the controller controls the motor so that the push rod reaches tothe door opening position when the door opening detecting portiondetermines that the refrigerator door is not opened before the push rodreaches to the door opening position.

According to yet another aspect of the present invention, there isprovided a control method of a refrigerator including a step in which amotor operates for opening a refrigerator door and a push rod moves froman initial position to a door opening position; a step in which acontroller determines whether the opening of the refrigerator door isdetected at a door opening detecting portion while the push rod isstopped at the door opening position; and a step in which the controllercontrols the motor based on whether the opening of the refrigerator dooris detected at the door opening detecting portion.

A step in which the controller controls the motor may include a step inwhich the controller controls the motor so that the push rod returns tothe initial position when the door opening detecting portion determinesthat the refrigerator door is opened before a certain time elapses whilethe push rod is stopped at the door opening position.

A step in which the controller controls the motor may include a step inwhich the controller controls the motor so that the push rod returns tothe initial position when the door opening detecting portion determinesthat the opening of the refrigerator door is not detected until acertain time elapses while the push rod is stopped at the door openingposition.

Advantageous Effects

According to the proposed invention, when it is detected that anexternal load acts on a door in a direction in which the door is closedin the moving process of a push rod for door opening, as a motor iscontrolled so that the push rod returns to an initial position, a damageof the push rod and/or a gear is prevented, and a damage of the motordue to an overload of the motor may be prevented.

Also, as a voltage is supplied to the motor while the push rod moves toa door opening position, the push rod moves to the initial position byany one of a weight of the door itself, a magnetic force of a magnetprovided in a gasket for the close contact of the door and a cabinet,and a closing force due to an auto-close mechanism for closing the doorautomatically, and thus a phenomenon in which the push rod moves to theinitial position and the door is closed may be prevented.

Also, the rotational speed of the motor is reduced in the process thatthe push rod moves from the initial position to the door openingposition, and accordingly, a moving speed of the push rod is reduced,and since the push rod stops at the door opening position while themoving speed of the push rod is reduced, a rattling phenomenon isprevented in the opening process of the door, and the rotation of afirst refrigerator door may be stopped smoothly.

Also, as it is detected that the door is opened at equal to or more thana reference angle larger than an opening angle of the door when the pushrod moves to the door opening position, and as the push rod returns tothe initial position, the push rod or the gear for transmitting power tothe push rod may be prevented from being damaged by the door beingclosed before the push rod returns to the initial position.

Also, as a door opening detecting portion is positioned adjacent to ahinge shaft, there is an advantage that it is possible to accuratelydetect that the door is rotated by equal to or more than the referenceangle.

Also, as the door opening detecting portion is positioned adjacent tothe hinge shaft, an interference with other configuration such as a dooropening device may be prevented.

Also, in the case in which a portion of the door opening detectingportion is provided in a hinge assembly, it is easy to assemble the dooropening detecting portion, and since it is easy to access the dooropening detecting portion by separating the hinge assembly, there is anadvantage that a service of the door opening detecting portion is easy.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a refrigerator according to a firstembodiment of the present invention;

FIG. 2 is a perspective view illustrating a door opening device providedat a first refrigerating compartment door according to the firstembodiment of the present invention;

FIG. 3 is a block diagram of the refrigerator according to the firstembodiment of the present invention;

FIG. 4 is a view illustrating the door opening device according to thefirst embodiment of the present invention;

FIG. 5 is a plan view illustrating the door opening device installed inthe first refrigerating compartment door according to the firstembodiment of the present invention;

FIG. 6 and FIG. 7 are flowcharts illustrating an operation of the dooropening device according to the first embodiment of the presentinvention;

FIG. 8 is a graph illustrating a rotational speed of a motor in a dooropening process;

FIG. 9 is a view illustrating an opening state of a door by a push rodmoving to a door opening position according to the first embodiment ofthe present invention;

FIG. 10 is a view illustrating a state in which the first refrigeratingcompartment door is opened by a reference angle according to the firstembodiment of the present invention;

FIG. 11 is a view illustrating a closing state of the firstrefrigerating compartment door according to a second embodiment of thepresent invention;

FIG. 12 is a view illustrating a state in which a door opening detectingportion detects an opening of the first refrigerating compartment dooraccording to the second embodiment of the present invention;

FIG. 13 is a view illustrating a closing state of the firstrefrigerating compartment door according to a third embodiment of thepresent invention;

FIG. 14 is a view illustrating a state in which the door openingdetecting portion detects an opening of the first refrigeratingcompartment door according to the third embodiment of the presentinvention; and

FIG. 15 is a flowchart illustrating an operation of the door openingdevice according to a fourth embodiment of the present invention;

MODES OF THE INVENTION

Hereinafter, some embodiments of the present invention will be describedin detail with reference to the accompanying illustrative drawings. Ingiving reference numerals to components of the drawings, the samereference numerals are given to the same components. Also, in thefollowing description of the present invention, if a detaileddescription of known functions and configurations is determined toobscure the interpretation of embodiments of the present invention, thedetailed description thereof will be omitted.

Further, in explaining the components of the embodiment of the presentinvention, a first, a second, A, B, (a), (b), and the like can be used.These terms are intended to distinguish one component from othercomponents, but the nature and the order or sequence of the componentsis not limited by those terms. When components are disclosed as“connected,” “coupled” or “contacted” to other components, the componentcan be directly connected or contacted to the other components, but itshould be understood that another component(s) could be “connected,”“coupled” or “contacted” there between.

FIG. 1 is a perspective view of a refrigerator according to a firstembodiment of the present invention, FIG. 2 is a perspective viewillustrating a door opening device provided at a first refrigeratingcompartment door according to the first embodiment of the presentinvention, and FIG. 3 is a block diagram of the refrigerator accordingto the first embodiment of the present invention.

With reference to FIGS. 1 to 3, a refrigerator 10 according to a firstembodiment of the present invention may include a cabinet 11 providedwith a storage compartment therein, and a refrigerator door 12 rotatablyor slidably connected to a front surface of the cabinet and selectivelyopens and closes the storage compartment.

In particular, the storage compartment may include one or more of arefrigerating compartment 111 and a freezing compartment 112.

The refrigerating compartment 111 may be opened and closed by arefrigerating compartment door 13, and the freezing compartment 112 maybe selectively opened and closed by a freezing compartment door 16.

Also, in the case in which the refrigerating compartment door 13 openingand closing the refrigerating compartment 111 is a rotary-type door, therefrigerating compartment door 13 may include a pair of doors 14 and 15which are rotatably connected to each of a front left edge and a frontright edge of the cabinet 11. That is, the refrigerating compartmentdoor 13 may include a first refrigerating compartment door 14 and asecond refrigerating compartment door 15.

In the case in which the freezing compartment door 16 opening andclosing the freezing compartment 112 is a rotary-type door, the freezingcompartment door 16 may include a pair of doors 17 and 18 which arerotatably connected to each of the front left edge and the front rightedge of the cabinet 11.

Also, in the case in which the freezing compartment door 16 is adrawer-type door opening and closing the freezing compartment 112 in asliding manner, a plurality of freezing compartment doors 16 may bearranged in a vertical direction or a horizontal direction.

The refrigerator 10 may further include a door opening device 25operating for opening the refrigerator door 12.

Hereinafter, an example in which the door opening device 25automatically opens the first refrigerating compartment door 14 of therefrigerator door 12 will be described, and the other door except thefirst refrigerating compartment door 14 may be automatically opened by astructure and a method described below.

The door opening device 25 may be disposed at a door needed to beopened. In one example, the door opening device 25 may be provided ateach of a plurality of refrigerating compartment doors for opening eachof the plurality of refrigerating compartment doors. Also, in the casein which one refrigerating compartment door includes a plurality ofdoors, the door opening device 25 may be provided at one or all doorsamong the plurality of doors.

At this point, the door opening device 25 may be positioned at an upperside portion of the door needed to be opened.

Also, the door opening device 25 may be provided at the freezingcompartment door 16 for opening the freezing compartment door 16.

In another example, the door opening device 25 may be provided in thecabinet 11. At this time, the door opening device 25 may be provided inthe same number with the number of the refrigerator doors 12.

Also, in the present embodiment, only a bottom freezer type refrigeratoris disclosed, but the spirit for door opening may be applied to variousrefrigerators such as a top mount type refrigerator, a side by side typerefrigerator, and a refrigerator having only a single storagecompartment and a door, etc.

The first refrigerating compartment door 14 may be connected to thecabinet 11 by a hinge assembly 30. The first refrigerating compartmentdoor 14 may be rotated by a hinge shaft (referring to 32 of FIG. 4)providing a center of rotation. The hinge shaft 32 of FIG. 4 may beprovided in the first refrigerating compartment door 14 and/or the hingeassembly 30.

The refrigerator 10 may further include a position detecting portion 28for detecting a position of a push rod (referring to 27 of FIG. 4)configuring the door opening device 25, and a motor rotation detectingportion 290 detecting a rotation of a motor 261 generating power foroperating the push rod 27 of FIG. 4, and a controller 20 controlling thedoor opening device 25 based on information detected from the positiondetecting portion 28 and the motor rotation detecting portion 290.

Also, the refrigerator 10 may further include a door opening detectingportion 40 for detecting whether the door is opened at equal to or morethan a reference angle, and the controller 20 may control the dooropening device 25 based on information detected from the door openingdetecting portion 40.

A control of the door opening device 25 by the controller 20 isdescribed later.

The refrigerator 10 may further include an input portion 50 forinputting a door opening command. The input portion 50 may be varioussuch as a switch turned on by a contact of a user, or a touch screenreceiving a command of the user, or a sensor detecting a gesture of theuser, and a structure and a method for imputing the door opening commandare not limited in the present invention.

Hereinafter the door opening device 25 will be described in detail.

FIG. 4 is a view illustrating the door opening device according to thefirst embodiment of the present invention, and FIG. 5 is a plan viewillustrating the door opening device installed in the firstrefrigerating compartment door according to the first embodiment of thepresent invention.

With reference to FIGS. 4 to 5, the door opening device 25 may bepositioned on an upper side portion of the first refrigeratingcompartment door 14. A frame 141 forming a space for accommodating thedoor opening device 25 may be provided in the upper side portion of thefirst refrigerating compartment door 14. The frame 141 may partition aspace in which an insulating material (not shown) is accommodated and aspace in which the door opening device 25 is accommodated in the firstrefrigerating compartment door 14.

In another example, the door opening device 25 may be positioned on alower side portion of the first refrigerating compartment door 14.

The door opening device 25 may include a housing 250 accommodated insidethe frame 141, a motor 261 installed in the housing 250 and generating adriving force, a push rod 27 operating by receiving the driving force ofthe motor 261, and a power transmitting mechanism transmitting thedriving force of the motor 261 to the push rod 27.

There is no limit but, the housing 250 may include a first housing 251,and a second housing 252 coupled with the first housing 251.

A coupling portion 253 coupled with a buffer portion 254 which mayabsorb shock or vibration may be provided in the first housing 251. Thebuffer portion 254 has a hole 255, and an installing portion 142 whichmay be inserted into the hole 255 of the buffer portion 254 may beprovided in the frame 141.

As the door opening device 25 is coupled to the frame 141 by the bufferportion 254, a vibration generated when the motor 261 is operated and avibration generated when the power transmitting mechanism is operatedare absorbed and a noise may be reduced, and the motor 261 and the powertransmitting mechanism may be prevented from transmitting the vibrationsto the first refrigerating compartment door 14.

The power transmitting mechanism may include one or more gears 262, 263,264, 265 and 266.

In the present invention, there is no limit on the number of gears aslong as the power transmitting mechanism may transmit power of the motor261 to the push rod 27, and in one example, the power transmittingmechanism is disclosed to include a plurality of gears 262, 263, 264,265 and 266 in FIG. 5.

In the case in which the push rod 27 is positioned in the firstrefrigerating compartment door 14, a length of the push rod 27 islimited but, the push rod 27 may include a curve-shaped rack gear 272for securing an opening angle of the first refrigerating compartmentdoor 14 by the push rod 27. At this time, the rack gear 272 may beengaged with a last gear of the plurality of gears 262, 263, 264, 265and 266.

As the rack gear 272 is formed in a curved shape, the length of the pushrod 27 may be reduced when the first refrigerating compartment door 14is to be opened by a required angle.

Therefore, even the push rod 27 is disposed on the first refrigeratingcompartment door 14, the opening of the first refrigerating compartmentdoor 14 is available by the push rod 27, and the opening angle may beincreased than a linearly shaped rack gear.

As the rack gear 272 is formed in a curved shape, the push rod 27 mayrotate relatively with a last gear when the last gear of the pluralityof gears 262, 263, 264, 265 and 266 is rotated.

That is, when the motor 261 is operated, the push rod 27 not only mayrotate with the first refrigerating compartment door 14 about the hingeshaft 32, but also rotate about the plurality of gears 262, 263, 264,265 and 266 and consequently may perform a relative curved motion aboutthe first refrigerating compartment door 14.

The rack gear 272 may be formed in an arc shape. At this time, the rackgear 272 may be disposed to be convex in a direction away from the hingeshaft 32.

When the push rod 27 performs the relative curved motion about the firstrefrigerating compartment door 14, a center of the curve-shaped rackgear 272 may coincide with the hinge shaft 32 so that the push rod 27may maintain a contact state with a front surface of the cabinet 11.

One or more guide ribs 257 are provided in any one of the housing 250and the push rod 27 so that the push rod 27 may move safely, and one ormore guide grooves 273 and 274 in which the one or more guide ribs 257are accommodated may be provided in the other one the housing 250 andthe push rod 27.

At this time, the one or more guide ribs 257 and the one or more guidegrooves 273 and 274 are may be formed in a curved shape. Or, the one ormore guide ribs 257 may be formed in a circular or rectangular shape,and the one or more guide grooves 273 and 274 may be formed in a curvedshape.

In one example, in FIG. 4, the one or more guide ribs 257 are providedin the housing 250, and the one or more guide grooves 273 and 274 aredisclosed to be provided in the push rod 27.

There is no limit, but each of the guide grooves 273 and 274 may beprovided on a first surface (an upper surface based on the figure) and asecond surface (a lower surface based on the figure) facing the firstsurface, and the guide rib 257 may be provided in each of the firsthousing 251 and the second housing 252.

The guide grooves 273 and 274 may be formed in an arc shape. At thistime, the guide grooves 273 and 274 may be disposed to convex in adirection away from the hinge shaft 32. And a center of the arc of theguide grooves 273 and 274 may be the hinge shaft 32.

Meanwhile, the push rod 27 may be positioned adjacent to the hinge shaft32. The more the push rod 27 is positioned adjacent to the hinge shaft32, the door opening device 25 is simplified and compact and the lengthof the push rod 27 may be reduced.

The hinge shaft 32 may be positioned on an upper surface of the firstrefrigerating compartment door 14. The first refrigerating compartmentdoor 14 may include a first side surface 14 a and a second side surface14 b facing the first side surface 14 a, and the hinge shaft 32 may bepositioned close to the first side surface 14 a.

That is, based on an imaginary line L bisecting the distance between thefirst side surface 14 a and the second side surface 14 b, the hingeshaft 32 may be positioned in an area corresponding to an area betweenthe imaginary line L and the first side surface 14 a.

And, the push rod 27 may be positioned between the motor 261 and thehinge shaft 32. Also, the push rod 27 may be positioned in the areacorresponding to the area between the imaginary line L and the firstside surface 14 a. At this time, the push rod 27 may be positionedbetween the imaginary line L and the hinge shaft 32.

Therefore, according to the present invention, as the push rod 27 ispositioned adjacent to the hinge shaft 32, the opening angle of thefirst refrigerating compartment door 14 may be increased by using ashort push rod 27.

By the one directional rotation of the motor 261, the plurality of gears262, 263, 264, 265 and 266 are rotated in a normal direction, andaccordingly, the push rod 27 may move in a direction in which the pushrod 27 is withdrawn from the first refrigerating compartment door 14 foropening the door.

On the other hand, by the other directional rotation of the motor 261,the plurality of gears 262, 263, 264, 265 and 266 are rotated in areverse direction, and the push rod 27 may be inserted into the firstrefrigerating compartment door 14.

At this time, during the opening process of the door or after the dooris opened, before the push rod 27 returns to an initial position, eachof the plurality of gears 262, 263, 264, 265 and 266 may be a spur gearso that each of the plurality of gears 262, 263, 264, 265 and 266 may berotated in the reverse direction by an external force applied to thepush rod 27.

Therefore, even the external force is applied to the push rod 27, theplurality of gears 262, 263, 264, 265 and 266 may be rotated in thereverse direction, and thus there is an advantage that a damage of theplurality of gears 262, 263, 264, 265 and 266 and the push rod 27 may beprevented.

Or, a portion or all of the plurality of gears 262, 263, 264, 265 and266 may be a multiple end spur gear having two gear bodies which havedifferent diameters.

Meanwhile, the position detecting portion 28 may include a firstposition sensor 281 and a second position sensor 282. In one example,the first position sensor 281 and the second position sensor 282 may bedisposed in the housing 250.

And, a magnet 275 may be provided in the push rod 27. The first positionsensor 281 and the second position sensor 282 may be a magneticdetecting sensor for detecting a magnetic of the magnet 275.

In the present document, a position of the push rod 27 when the firstposition sensor 281 detects the magnet 275 or a position of the push rod27 when the first position sensor 281 faces the magnet 275 may be aninitial position.

A position of the push rod 27 when the second position sensor 282detects the magnet 275 or a position of the push rod 27 when the secondposition sensor 282 faces the magnet 275 may be a door opening position(or a final position).

In the present embodiment, the first refrigerating compartment door 14may be opened in the process that the push rod 27 moves from the initialposition to the door opening position.

In the present document, “door opens” means that the storage compartmentopened and closed by the door is communicated with outside therefrigerator 10.

The controller 20 may control the motor 261 based on informationdetected from each of the position sensors 281 and 282. In one example,the controller 20 may rotate the motor 261 in one direction and may stopthe motor 261 when it is detected that the push rod 27 moves to the dooropening position.

When the push rod 27 is moved to the door opening position and a certaintime elapses while the motor 261 is stopped, the controller 20 mayrotate the motor 261 in the other direction so that the push rod 27returns to the initial position.

According to the present embodiment, the reason for rotating the motor261 in the other direction after the motor is stopped and then a certaintime elapses is to maintain a state in which the first refrigeratingcompartment door 14 is opened.

That is, in the case in which the push rod 27 moves to the door openingposition and immediately returns to the initial position withoutmaintaining the suspended state, a problem that the first refrigeratingcompartment door 14 is closed immediately occurs by one or more ofweight of the first refrigerating compartment door 14 itself (includingthe weight of food stored in the first refrigerating compartment door14), a magnetic force provided in a gasket (not shown) for the closecontact of the first refrigerating compartment door 14 and the cabinet11, and a closing force by an auto-close mechanism (not shown) providedin the hinge assembly 30 for the door to be closed automatically.

However, like the present invention, in the case in which the motor 261is rotated in the other direction after the motor 261 is stopped andthen a certain time elapses, since the first refrigerating compartmentdoor 14 may maintain a opened state during the certain time, the usermay easily increase the opening angle of the first refrigeratingcompartment door 14 manually.

In another example, the first position sensor 281 and the secondposition sensor 282 may be a light sensor. And, a groove or a projectionportion may be provided in the push rod 27 and each of the positionsensors 281 and 282 may detect the groove or the projection portion. Aconfiguration for detecting a position of the push rod 27 is not limitedin the present embodiment.

Meanwhile, the door opening detecting portion 40 may include a magnet420 provided in any one of the first refrigerating compartment door 14and the hinge assembly 30, and a detecting sensor 410 provided in theother one of the first refrigerating compartment door 14 and the hingeassembly 30 and detecting a magnetic of the magnet 420.

In one example, in FIG. 5, the detecting sensor 410 is disclosed to bedisposed in the hinge assembly 30.

In the case in which the detecting sensor 410 is provided in the hingeassembly 30, an assembly and service of the detecting sensor 410 may beeasy. That is, the detecting sensor 410 may be accessed by separatingthe hinge assembly 30, without separating the first refrigeratingcompartment door 14.

The detecting sensor 410 and the magnet 420 may be disposed adjacent tothe hinge shaft 32. Therefore, in the rotating process of the firstrefrigerating compartment door 14, the detecting sensor 410 may detectthe magnetic of the magnet 420 of the first refrigerating compartmentdoor 14 directly, and thus may accurately detect that the firstrefrigerating compartment door 14 is rotated at the reference angle.

Also, as the detecting sensor 410 and the magnet 420 are positionedadjacent to the hinge shaft 32, door opening may be detected withoutinterference with another configuration of surroundings.

When the magnet 420 is positioned below the detecting sensor 410 in theopening process of the first refrigerating compartment door 14, thedetecting sensor 410 detects the magnetic of the magnet 420, and thecontroller 20 may control the motor 261 so that the push rod 27 returnsto the initial position.

Meanwhile, the motor rotation detecting portion 290 may detect arotation of an axis of the motor 261. In one example, a rotation platemay be connected to the axis of the motor 261. A plurality of slits maybe spaced in a circumferential direction and arranged in the rotationplate.

In one example, the motor rotation detecting portion 290 may include alight emitting portion positioned on one side portion of the rotationplate and a light receiving portion positioned on the other side portionof the rotation plate.

Therefore, when the rotation plate is rotated together when the motor261 is rotated, the motor rotation detecting portion 290 may detect thenumber of slits when the rotation plate is rotated. That is, the motorrotation detecting portion 290 outputs a pulse when it detects the slit,and the controller 20 may determine the rotational speed rpm of themotor 261 based on the pulse output from the motor rotation detectingportion 290, and may determine the moving distance of the push rod 27.

Hereinafter, an operation of the door opening device 25 is described.

FIG. 6 and FIG. 7 are flowcharts illustrating an operation of the dooropening device according to the first embodiment of the presentinvention, FIG. 8 is a graph illustrating a rotational speed of a motorin a door opening process, FIG. 9 is a view illustrating an openingstate of a door by the push rod moving to a door opening positionaccording to the first embodiment of the present invention, and FIG. 10is a view illustrating a state in which the first refrigeratingcompartment door is opened by a reference angle according to the firstembodiment of the present invention.

With reference to FIGS. 1 to 9, power of the refrigerator 10 is turnedon (S1).

When the power of the refrigerator 10 is turned on in step S1, thecontroller 20 determines whether the push rod 27 is positioned in theinitial position (S2).

As a determination result in step S2, in the case in which the push rod27 is not positioned in the initial position, the controller 20 operatesthe motor 261 so that the push rod 27 moves to the initial position(S3).

A state in which the push rod 27 is positioned in the initial positionis a state in which the first position sensor 281 detects the magnet 275of the push rod 27.

While the push rod 27 is positioned in the initial position, thecontroller 20 determines whether a door openings signal is input throughthe input portion 50 (S4).

As a determination result in step S4, when it is determined that thedoor opening signal is input, the controller 20 controls the motor 261to be rotated in one direction for moving the push rod 27 from theinitial position to the door opening position (S5).

That is, the controller 20 may supply a voltage to the motor 261 so thatthe motor 261 is rotated in a first direction for moving the push rod 27from the initial position to the door opening position.

When the motor 261 is rotated in one direction, the plurality of gears262, 263, 264, 265 and 266 are rotated in a normal direction, and thepush rod 27 pushes the cabinet 11 and in a reaction to this, the firstrefrigerating compartment door 14 is rotated.

While the motor 261 is rotated in one direction, the controller 20determines whether an external load acts on the first refrigeratingcompartment door 14 in a direction in which the first refrigeratingcompartment door 14 is closed (S6).

Specifically, when the motor 261 is rotated, a pulse is output from themotor rotation detecting portion 290. At this time, when the externalload acts on the first refrigerating compartment door 14, the rotationalspeed of the motor 261 is reduced, and accordingly, the number of pulsesoutput per unit time in the motor rotation detecting portion 290 isreduced.

Therefore, when the number of pulses output per unit time is equal to orless than the number of first detected loads, the external load may bedetermined to act on the first refrigerating compartment door 14.

However, in the initial operation of the motor 261, since the number ofpulses output per unit time in the motor rotation detecting portion 290may be equal to or less than the number of first detected loads,determination whether the external load is detected may be performedafter the motor 261 operates in one direction and a certain timeelapses.

If, in the case in which the motor 261 keeps operating while the numberof pulses output per unit time in the motor rotation detecting portion290 is equal to or less than the number of first detected loads, thepush rod 27 and/or the gear may be damaged or the motor 261 may bedamaged by the overload of the motor 261.

Therefore, in the present embodiment, when it is determined that theexternal load acts on the first refrigerating compartment door 14, thecontroller 20 rotates the motor 261 in the other direction so that thepush rod 27 returns to the initial position (S14).

Meanwhile, as a determination result in step S6, when it is determinedthat the external load is not detected, the controller 20 determineswhether the door opening detecting portion 40 detects door opening (S7).

In the present document, a case in which the door opening detectingportion 40 detects door opening while the motor 261 is rotated in onedirection is a case in which the user rotates the first refrigeratingcompartment door 14 in a direction in which the first refrigeratingcompartment door 14 is opened.

At this time, an opening angle θ2 of the first refrigerating compartmentdoor 14 when the door opening detecting portion 40 detects the dooropening is larger than an opening angle θ1 of the first refrigeratingcompartment door 14 when the push rod 27 moves to the door openingposition.

When rotated at equal to or more than the reference angle in the processthat the first refrigerating compartment door 14 is rotated for theopening, the door opening detecting portion 40 may detect the dooropening.

A projecting length of the push rod 27 from the first refrigeratingcompartment door 14 is increased while the motor 261 is rotated in onedirection. If, the first refrigerating compartment door 14 is closedafter the opening angle of the first refrigerating compartment door 14is increased while the push rod 27 protrudes from the firstrefrigerating compartment door 14, the push rod 27 collides with thecabinet 11, and there is a problem that the push rod 27 is damaged orgears configuring the power transmitting mechanism is damaged.

At this time, as the opening angle of the first refrigeratingcompartment door 14 is larger, a greater impact force is applied to thepush rod 27 when the first refrigerating compartment door 14 is closed.Also, as the projecting length of the push rod 27 from the firstrefrigerating compartment door 14 is longer, the possibility of damageof the push rod 27 is increased.

In the present embodiment, while the motor 261 is rotated in onedirection, in order to prevent the damage of gears configuring the pushrod 27 and/or the power transmitting mechanism due to the firstrefrigerating compartment door 14 closed after being opened by the user,in the case in which the door opening is detected at the door openingdetecting portion 40, the controller 20 rotates the motor 261 in theother direction so that the push rod 27 returns to the initial position(S14).

In the present embodiment, in the process that the motor 261 operates inone direction and the push rod 27 moves from the initial position to thedoor opening position, when the door opening detecting portion 40detects the door opening, the push rod 27 may return to the initialposition by rotating the motor 261 in the other direction even beforethe push rod 27 moves to the door opening position.

Therefore, in the process that the first refrigerating compartment door14 is rotated in a reclosing direction after being rotated at equal toor more than the reference angle, since the push rod 27 moves to theinitial position, the damage of the push rod 27 and the gears by thecollision of the push rod 27 and the cabinet 11 may be prevented.

Meanwhile, as a determination result in step S7, in the case in whichthe door opening is not detected at the door opening detecting portion40 while the motor 261 is rotating in one direction, the controller 20may determine whether the push rod 27 reaches to the door openingposition (S8).

That is, when the motor 261 is rotated in one direction while the pushrod 27 is positioned in the initial position, the push rod 27 is moved,and in this process, the magnet 275 of the push rod 27 is not detectedin the first position sensor 281. And, in the moving process of the pushrod 27, when the magnet 275 of the push rod 27 is detected at the secondposition sensor 282, the controller 20 may determine that the push rod27 reaches to the door opening position.

As a determination result in step S8, when it is determined that thepush rod 27 reaches to the door opening position, the controller 20stops the motor 261 (S9).

In the case in which the rotational speed of the motor 261 is constantwhen the motor 261 is rotated in one direction and the push rod 27 movesfrom the initial position to the door opening position, the push rod 27reaches to the door opening position, and the first refrigeratingcompartment door 14 can't stop smoothly and rattes in the process of themotor 261 being stopped. In this case, the user's emotional complaintsmay be caused.

Therefore, in the present embodiment, in the process that the motor 261is rotated in one direction and the push rod 27 moves from the initialposition to the door opening position, the rotational speed of the motor261 is to be varied.

Specifically, with reference to FIG. 8, the controller 20 may controlthe motor 261 so that the motor 261 is rotated in a first referencespeed until the number of pulses detected from the motor rotationdetecting portion 290 reaches to a first reference number.

And, when the number of pulses detected from the motor rotationdetecting portion 290 reaches to the first reference number, thecontroller 20 may control the motor 261 to reduce the rotational speedthereof until the number of pulses detected from the motor rotationdetecting portion 290 reaches to a second reference number which islarger than the first reference number.

At this time, the controller 20 may control the rotational speed of themotor 261 to be reduced linearly or non-linearly.

And when the rotational speed of the motor 261 reaches to the secondreference speed, the controller 20 may control the motor 261 to maintainthe rotational speed thereof in the second reference speed. And, whenthe second position sensor 282 detects the magnet 275 of the push rod 27while the rotational speed of the motor 261 is maintained in the secondreference speed, the controller 20 may stop the motor 261.

Therefore, according to the embodiment, the moving speed of the push rod27 is decreased while the push rod 27 moves from the initial position tothe door opening position, and since the push rod 27 stops at the dooropening position while the speed is decreased, a rattling phenomenon inthe opening process of the first refrigerating compartment door 14 isprevented, and the first refrigerating compartment door 14 may besmoothly stopped.

At this time, a point of time when the number of pulses output from themotor rotation detecting portion 290 reaches to the first referencenumber may be a one point between a point bisecting a distance betweenthe initial position and the door opening position of the push rod 27and the door opening position.

As the rotational speed of the motor 261 is faster, the door openingtime may be reduced.

Like in the present invention, in the case in which the point at whichthe number of pulses output from the motor rotation detecting portion290 reaches to the first reference number is one point between the pointbisecting the initial position and the door opening position of the pushrod 27 and the door opening position, a high speed rotation time of themotor 261 may be sufficiently secured, and thus the door opening timemay be reduced and the rattling of the door when the door is opened maybe prevented.

Meanwhile, in the case in which the push rod 27 reaches to the dooropening position, a portion of a rear surface 14 c of the firstrefrigerating compartment door 14 may be positioned forward than a frontsurface 15 a of the second refrigerating compartment door 15, andaccordingly, a gap of a certain distance may be formed between one sideend of the rear surface 14 c of the first refrigerating compartment door14 and one side end of the front surface 15 a of the secondrefrigerating compartment door 15.

In the case in which both hands of the user are not available, the gapmay be set so as to allow the user's elbow or foot to be inserted.

There is no limit, but the gap may be equal to or more than 40 mm. Thatis, a minimum horizontal distance between the rear surface 14 c of theopened first refrigerating compartment door 14 and the front surface 15a of the closed second refrigerating compartment door 15 may be 40 mm.

In order for the gap to be equal to or more than 40 mm, the openingangle θ1 of the first refrigerating compartment door 14 may be equal toor more than 19 and less than 30 degrees at a position in which the pushrod 27 reaches to the door opening position.

In the present embodiment, since the push rod 27 includes thecurve-shaped rack gear 272, and is positioned adjacent to the hingeshaft 32, the projecting length of the push rod 27 is reduced but theopening angle θ1 of the first refrigerating compartment door 14 may besecured at the position in which the push rod 27 reaches to the dooropening position.

Therefore, while the first refrigerating compartment door 14 is rotatedat a certain angle, the opening angle θ1 of the first refrigeratingcompartment door 14 may be increased manually by inserting an elbow orfoot to the gap.

Meanwhile, while the push rod 27 reaches to the door opening positionand the motor 261 is stopped, the controller 20 supplies a voltage tothe motor 261 so as to maintain a state in which the push rod 27 isstopped at the door opening position (S10).

That is, the controller 20 stops the motor 261 when the push rod 27moves to the door opening position, and supplies the voltage to themotor 261 so as to maintain a state in which the push rod 27 is stoppedat the door opening position while the motor 261 is stopped.

As described above, the push rod 27 is pushed toward the initialposition by one or more of a weight of the first refrigeratingcompartment door 14 itself, a magnetic force of the magnet provided inthe gasket (not shown) for the close contact of the first refrigeratingcompartment door 14 and the cabinet 11, and a closing force generated bythe auto-close mechanism (not shown) provided in the hinge assembly 30for the door to be closed automatically. In this case, a phenomenon thatthe motor 261 is rotated in other direction may occur.

However, in the present embodiment, since the voltage is supplied to themotor 261 so that the push rod 27 is maintained in the suspended stateat the door opening position, the state in which the push rod 27 isstopped without being moved is maintained, and accordingly, the rotationof the motor 261 in the other direction is prevented.

However, a supply cycle of the voltage supplied to the motor 261 may beset based on the size of an external force acting on the push rod 27.

That is, even if the voltage is supplied to the motor 261, an axis ofthe motor 261 is not rotated due to the external force acting on thepush rod 27, and the push rod 27 may maintain the suspended state.Therefore, even if the voltage is supplied to the motor 261, the pulseis not output from the motor rotation detecting portion 290.

The rotational speed of the motor 261 according to the embodiment may bevaried by a duty of the voltage supplied to the motor 261. A certainsize of voltage may be supplied to the motor 261 periodically, and theshorter the supply period of the voltage supplied to the motor 261 (orthe larger the duty), the faster the rotational speed of the motor 261may be.

In the present embodiment, the supply period of the voltage supplied tothe motor 261 when the motor 261 maintains the second reference speed islonger than the supply period of the voltage supplied to the motor 261when the push rod 27 reaches to the door opening position.

While the motor 261 is stopped, the controller 20 determines whether theexternal load acting on the first refrigerating compartment door 14 isdetected in the direction in which the first refrigerating compartmentdoor 14 is closed (S11).

Specifically, while the motor 261 is stopped, the pulse is not outputfrom the motor rotation detecting portion 290. However, when theexternal load acts on the first refrigerating compartment door 14, sincethe motor 261 is rotated in the other direction, the pulse is outputfrom the motor rotation detecting portion 290.

Therefore, when the number of pulses output per unit time is equal to ormore than the number of second detected loads, it is determined that theexternal load acts on the first refrigerating compartment door 14. Inthe case in which the user forcibly closes the first refrigeratingcompartment door 14 while the motor 261 is stopped, there is a fear thatthe push rod 27 and or the gear may be damaged.

Therefore, in the present embodiment, when it is determined that theexternal load acts on the first refrigerating compartment door 14 whilethe push rod 27 is stopped at the door opening position, the controller20 rotates the motor 261 in the other direction so that the push rod 27returns to the initial position (S14).

Meanwhile, as a determination result in step S11, when it is determinedthat the external load does not act, the controller 20 determineswhether the door opening detecting portion 40 detects the door opening(S12).

A case in which the door opening detecting portion 40 detects the dooropening while the push rod 27 reaches to the door opening position is acase in which the user increases the opening angle of the firstrefrigerating compartment door 14.

As described above, the opening angle θ1 of the first refrigeratingcompartment door 14 while the push rod 27 reaches to the door openingposition is smaller than the opening angle θ2 of the first refrigeratingcompartment door 14 while the door opening detecting portion 40 detectsthe opening of the first refrigerating compartment door 14.

Therefore, in the case in which the opening angle θ1 of the firstrefrigerating compartment door 14 is increased while the push rod 27reaches to the door opening position, the door opening detecting portion40 detects the door opening.

As a determination result in step S12, when it is determined that thedoor opening detecting portion 40 detects the opening of the door, thecontroller 20 may rotate the motor 261 in the other direction so thatthe push rod 27 returns to the initial position (S14).

In the case in which the first refrigerating compartment door 14 isrotated in a reclosing direction after rotated at equal to or more thanthe reference angle while the push rod 27 stops at the door openingposition, the push rod 27 and or the gear may be damaged.

According to the embodiment, even before a certain time elapses whilethe push rod 27 is positioned at the door opening position, when it isdetermined that the opening of the door is detected at the door openingdetecting portion 40, as the controller 20 rotates the motor 261 in theother direction so that the push rod 27 returns to the initial position,the damage of the push rod 27 and/or the gears may be prevented.

As a determination result in step S12, when it is determined that theopening of the door is not detected at the door opening detectingportion 40, the controller 20 may determine whether a certain timeelapses after the push rod 27 reaches to the door opening position orthe motor 261 is stopped (S13).

When the certain time elapses after the push rod 27 reaches to the dooropening position, the controller 20 may control the motor 261 to berotated in the other direction in order to return the push rod 27 to theinitial position.

While the motor 261 is rotated in the other direction, the controller 20may determine whether the push rod 27 reaches to the initial position(S15).

When it is determined that the push rod 27 reaches to the initialposition, the controller 20 may stop the motor 261 (S16).

In the embodiment above, although it is described that the door openingdetecting portion 40 includes the magnetic sensor and the magnet 275, incontrast, the door opening detecting portion 40 may include a lightsensor.

In one example, the light sensor may include a light emitting portionprovided in any one of the hinge assembly 30 and the first refrigeratingcompartment door 14 and a light receiving portion provided in the otherone thereof, and when the first refrigerating compartment door 14 isrotated at the reference angle, light emitted from the light emittingportion may reach to the light receiving portion. And, when the lightreaches to the light receiving portion, the controller 20 may controlthe motor 261 so that the push rod 27 returns to the initial position.

Or, the light emitting portion and the light receiving portion areprovided in any one of the hinge assembly 30 and the first refrigeratingcompartment door 14, and a reflecting plate may be provided in the otherone thereof. And when the first refrigerating compartment door 14 isrotated at the reference angle, the light emitted from the lightemitting portion is reflected by the reflecting plate and may reach tothe light receiving portion. And, when the light reaches to the lightreceiving portion, the controller 20 may control the motor 261 so thatthe push rod 27 returns to the initial position.

Also, in the embodiment above, the position of the push rod 27 isdetected by the position detecting portion 28 and the motor 261 iscontrolled based on this. In contrast, the operation of the motor 261may be controlled based on the operating time of the motor 261. Forexample, the motor 261 is operated for the door opening and when a firstreference time elapses, the motor 261 may be stopped. Also the motor 261is operated for returning the push rod 27 to the initial position andthe motor 261 may be stopped when a second reference time elapses.

FIG. 11 is a view illustrating a closing state of the firstrefrigerating compartment door according to a second embodiment of thepresent invention. FIG. 12 is a view illustrating a state in which adoor opening detecting portion detects an opening of the firstrefrigerating compartment door according to the second embodiment of thepresent invention.

The present embodiment is same as the first embodiment in the otherpart, but different in a door opening detecting portion. Therefore,hereinafter, only a characteristic part of the present embodiment willbe described.

With reference to FIGS. 11 to 12, a door opening detecting portion 50according to a second embodiment, may include a micro switch 510 whichis turned on when the first refrigerating compartment door 14 is rotatedat a reference angle.

The micro switch 510 may be provided in any one of the hinge assembly 30and the first refrigerating compartment door 14.

The door opening detecting portion 50 is provided in the other one ofthe hinge assembly 30 and the first refrigerating compartment door 14.When the first refrigerating compartment door 14 is rotated at thereference angle, a switch control portion 520 may be further includedfor turning on the micro switch 510.

According to the arrangement of the micro switch 510 and the switchcontrol portion 520, in the case in which the first refrigeratingcompartment door 14 is rotated at less than the reference angle, themicro switch 510 maintains an off state, and when the micro switch 510is rotated at equal to or more than the reference angle, the microswitch 510 may maintain an on state by the switch control portion 520.

Or according to the arrangement of the micro switch 510 and the switchcontrol portion 520, in the case in which the first refrigeratingcompartment door 14 is rotated at less than the reference angle, themicro switch 510 maintains the off state, and when the micro switch isrotated at the reference angle, the micro switch 510 is turned on by theswitch control portion 520, and when the micro switch 510 is rotated atequal to or more than the reference angle, the micro switch 510 may beturned off again.

In any case, when the first refrigerating compartment door 14 is rotatedat the reference angle, the micro switch 510 may be turned on, and whenit is detected that the micro switch 510 is turned on, the controller 20may control the motor 261 so that the push rod 27 returns to the initialposition while the push rod 27 moves to the door opening position orstops at the door opening position.

In the present embodiment, the micro switch 510 may be disposed on aposition adjacent to the hinge shaft 32.

In the case in which the micro switch 510 disposed in the firstrefrigerating compartment door 14, when the first refrigeratingcompartment door 14 is rotated centering on the hinge shaft 32, since arotating radius of the micro switch 510 is small, the length of theswitch control portion 520 may be minimized.

In the case in which the micro switch 510 is disposed in the hingeassembly 30, the switch control portion 520 may be positioned adjacentto the hinge shaft 32. Even in this case, when the first refrigeratingcompartment door 14 is rotated centering on the hinge shaft 32, sincethe rotating radius of the switch control portion 520 is small, thelength of the switch control portion 520 may be minimized.

Also according to the present embodiment, when the first refrigeratingcompartment door 14 is rotated at equal to or more than the referenceangle, since the micro switch 510 is turned on, it may be accuratelydetected that the first refrigerating compartment door 14 is rotated atequal to or more than the reference angle.

Also, as the micro switch 510 and the switch control portion 520 arepositioned adjacent to the hinge shaft 32, the door opening may bedetected without interference with other configuration of surrounding.

FIG. 13 is a view illustrating a closing state of the firstrefrigerating compartment door according to a third embodiment of thepresent invention, and FIG. 14 is a view illustrating a state in whichthe door opening detecting portion detects an opening of the firstrefrigerating compartment door according to the third embodiment of thepresent invention.

The present embodiment is same as the first embodiment in the otherpart, but different in a door opening detecting portion. Therefore,hereinafter, only a characteristic part of the present embodiment willbe described.

With reference to FIGS. 13 to 14, a door opening detecting portion 60according to a third embodiment of the present embodiment may include amagnet sensor 610 turned off when the first refrigerating compartmentdoor 14 is rotated at a reference angle, and a magnet 620 which mayprovide a magnetic force to the magnet sensor 610.

The magnet sensor 610 is a sensor which is turned on since a point ofcontact is attached in the case in which a magnetic force of a certainsize is acting, and turned off since the point of contact is separatedin the case in which a magnetic force equal to or less than the certainsize is acting, and since a known sensor may be used, a detaileddescription will be omitted.

The magnet sensor 610 may be provided in any one of the hinge assembly30 and the first refrigerating compartment door 14, and the magnet 620may be provided in the other one of the hinge assembly 30 and the firstrefrigerating compartment door 14.

In the case in which the first refrigerating compartment door 14 isrotated at less than the reference angle, the magnet sensor 610maintains the on state by the magnetic force of the magnet 620, and inthe case in which the first refrigerating compartment door 14 is rotatedat equal to or more than the reference angle, the magnet sensor 610 maybe turned off.

At this time, even if the strength of the magnetic force of the magnet620 is not strong, in order to turn off the magnet sensor 610 only inthe case in which the first refrigerating compartment door 14 is rotatedat equal to or more than the reference angle, the magnet sensor 610 andthe magnet 620 may be positioned adjacent to the hinge shaft 32.

Also, as the magnet sensor 610 and the magnet 620 are positionedadjacent to the hinge shaft 32, the door opening may be detected withoutinterference with other configuration of the surrounding.

In the embodiments above, the magnetic sensor, micro switch, lightsensor, and magnet sensor may be collectively called as a sensoroutputting a signal corresponding a case in which the refrigerator dooris rotated at equal to or more than the reference angle.

FIG. 15 is a flowchart illustrating an operation of the door openingdevice according to a fourth embodiment of the present invention.

The present embodiment is same as the first embodiment in the otherpart, but proposes a simplified control method of the door openingdevice than the control method of the door opening device of the firstembodiment. Therefore, hereinafter, only a characteristic part of thepresent embodiment will be described.

With reference to FIG. 15, while the first refrigerating compartmentdoor 14 closes the refrigerating compartment 111, the push rod 27 may bepositioned in an initial position. In the initial position, the firstposition sensor 281 detects the magnet 275 of the push rod 27.

While the push rod 27 is positioned in the initial position, the pushrod 27 is in contact with the front surface of the cabinet 11 or may bespaced apart from the front surface of the cabinet 11.

When it is determined that a door opening signal is input, thecontroller 20 controls the motor 261 to be rotated in one direction(S21).

When the motor 261 is rotated in one direction, the plurality of gears262, 263, 264, 265 and 266 are rotated in a normal direction, the pushrod 27 pushes the cabinet 11 and in a reaction to this, the firstrefrigerating compartment door 14 is rotated.

While the motor 261 is rotated in one direction, the controller 20determines whether the door opening detecting portion 40 detects thedoor opening (S22).

In the present document, a case in which the door opening detectingportion 40 detects the door opening while the motor 261 is rotated inone direction is a case in which the user rotates the firstrefrigerating compartment door 14 in a direction in which the firstrefrigerating compartment door 14 is opened.

At this time, the opening angle θ2 of the first refrigeratingcompartment door 14 when the door opening detecting portion 40 detectsthe door opening is larger than the opening angle θ1 of the firstrefrigerating compartment door 14 when the push rod 27 moves to the dooropening position.

In the process that the first refrigerating compartment door 14 isrotated for the opening, when the first refrigerating compartment door14 is rotated at equal to or more than the reference angle, the dooropening detecting portion 40 may detect the door opening.

In the present embodiment, for preventing the damage of the push rod 27and/or the gears configuring the power transmitting mechanism in theprocess that the first refrigerating compartment door 14 is closed afterbeing opened by the user while the motor 261 is rotated in onedirection, in the case in which the door opening is detected at the dooropening detecting portion 40 while the motor 261 is rotated in onedirection, the controller 20 rotates the motor 261 in the otherdirection so that the push rod 27 returns to the initial position (S27).

According to the present embodiment, in the case in which the dooropening detecting portion 40 detects the door opening in the processthat the motor 261 is rotated in one direction and the push rod 27 movesfrom the initial position to the door opening position, as the motor 261is rotated in the other direction even before the push rod 27 moves tothe door opening position, the push rod 27 may return to the initialposition.

Therefore, in the process that the first refrigerating compartment door14 is rotated in the reclosing direction after being rotated at equal toor more than the reference angle, since the push rod 27 moves to theinitial position, the damage of the push rod 27 and the gears due to thecollision of the push rod 27 and the cabinet 11 may be prevented.

Meanwhile, as a determination result in step S22, in the case in whichthe door opening is not detected from the door opening detecting portion40 while the motor 261 is rotated in one direction, the controller 20may determine whether the push rod 27 reaches to the door openingposition (S23).

That is, when the motor 261 is rotated in one direction while the pushrod 27 is positioned in the initial position, the push rod 27 is moving,and in this process, the magnet 275 of the push rod 27 is not detectedat the first position sensor 281. And in the moving process of the pushrod 27, when the magnet 275 of the push rod 27 is detected at the secondposition sensor 282, the controller 20 may determine that the push rod27 reaches to the door opening position.

As a determination result in step S23, when it is determined that thepush rod 27 reaches to the door opening position, the controller 20 maystop the motor 261 (S24).

In the case in which the push rod 27 reaches to the door openingposition, a portion of the rear surface 14 c of the first refrigeratingcompartment door 14 may be positioned forward than the front surface 15a of the second refrigerating compartment door 15, and accordingly, acertain distance gap may be formed between one side end of the rearsurface 14 c of the first refrigerating compartment door 14 and one sideend of the front surface 15 a of the second refrigerating compartmentdoor 15.

In the case in which both hands of the user are not available, the gapmay be set so as to allow the user's elbow or foot to be inserted.

Therefore, while the first refrigerating compartment door 14 is rotatedin a certain angle, the opening angle θ1 of the first refrigeratingcompartment door 14 may be increased manually by inserting the elbow orfoot to the gap.

Meanwhile, while the push rod 27 reaches to the final position and themotor 261 is stopped, the controller 20 may determine whether the dooropening detecting portion 40 detects the door opening (S25).

A case in which the door opening detecting portion 40 detects the dooropening while the push rod 27 reaches to the door opening position is acase in which the user increases the opening angle of the firstrefrigerating compartment door 14.

As described above, the opening angle θ1 of the first refrigeratingcompartment door 14 while the push rod 27 reaches to the door openingposition is smaller than the opening angle θ2 of the first refrigeratingcompartment door 14 when the door opening detecting portion 40 detectsthe opening of the first refrigerating compartment door 14.

Therefore, in the case in which the opening angle of the firstrefrigerating compartment door 14 is increased while the push rod 27reaches to the door opening position, the door opening detecting portion40 detects the door opening.

As a determination result in step S25, when it is determined that thedoor opening detecting portion 40 detects the opening of the door, thecontroller may rotate the motor 261 in the other direction so that thepush rod 27 returns to the initial position (S27).

Even if the first refrigerating compartment door 14 is rotated in thereclosing direction after being rotated at equal to or more than thereference angle while the push rod 27 reaches to the door openingposition, the push rod 27 and/or the gears may be damaged.

Therefore, in the present embodiment, even before a certain time elapseswhile the push rod 27 is positioned in the door opening position, whenit is determined that the opening of the door is detected at the dooropening detecting portion 40, as the controller 20 rotates the motor 261in the other direction so that the push rod 27 returns to the initialposition, the damage of the push rod 27 and/or the gears may beprevented.

As a determination result in step S25, when it is determined that theopening of the door is not detected at the door opening detectingportion 40, the controller 20 may determine whether a certain timeelapses from a point of time when the push rod 27 reaches to the dooropening position or a point of time when the motor 261 is stopped (S26).

If the time when the push rod 27 reaches to the door opening positionelapses for the certain time, the controller 20 may control the motor261 to be rotated in the other direction for returning the push rod 27to the initial position.

While the motor 261 is rotated in the other direction, the controller 20may determine whether the push rod 27 reaches to the initial position(S28).

When it is determined that the push rod 27 reaches to the initialposition, the controller 20 may stop the motor 261 (S29).

The invention claimed is:
 1. A refrigerator comprising: a cabinet inwhich a storage compartment is formed; a refrigerator door that isconfigured to open and close the storage compartment; a door openingdevice with a push rod that is configured to move from an initialposition to a door opening position to open the refrigerator door and amotor that provides power to the push rod; and a controller that isconfigured to control the motor, wherein the controller controls thepush rod to move to the door opening position while in close contactwith the cabinet or the refrigerator door in order to open therefrigerator door by rotating the motor in a first direction, controlsthe motor so that the motor is rotated in a first direction in order tothe move the push rod from the initial position to the door openingposition, stops the motor when the push rod moves to the door openingposition, and controls the motor so as to maintain a state in which thepush rod is stopped at the door opening position, and rotates the motorin a second direction opposite to the first direction so that the pushrod returns from the door opening position to the initial position, whena certain time elapses from a point of time when the rotation of themotor is stopped.
 2. The refrigerator according to claim 1, wherein thepush rod includes an arc-shaped rack gear which may receive the power ofthe motor.
 3. The refrigerator according to claim 1, wherein thecontroller controls the motor so that a rotational speed of the motor isreduced in the process that the push rod moves from the initial positionto the door opening position.
 4. The refrigerator according to claim 3,wherein the controller controls the motor so that the motor is rotatedin a first rotational speed, and at a certain point of time, thecontroller controls the motor so that the rotational speed of the motorbecomes a second rotational speed which is lower than the firstrotational speed.
 5. The refrigerator according to claim 4, wherein whenthe rotational speed of the motor reaches to the second rotationalspeed, the controller controls the motor so that the rotational speed ofthe motor is maintained in the second rotational speed until the pushrod reaches to the door opening position.
 6. The refrigerator accordingto claim 4, further comprising a motor rotation detecting portion fordetecting the rotation of the motor, wherein the motor rotationdetecting portion outputs a pulse in the rotation process of the motor,and the certain point of time is a point of time when the number ofpulses output from the motor rotation detecting portion reaches to afirst reference number.
 7. The refrigerator according to claim 6,wherein the speed of the motor at a point of time when the number ofpulses output from the motor rotation detecting portion reaches to asecond reference number which is larger than the first reference numberis the second rotational speed.
 8. The refrigerator according to claim1, further comprising a motor rotation detecting portion for detectingthe rotation of the motor, wherein while the motor is rotated in onedirection for opening the refrigerator door and the push rod moves fromthe initial position to the door opening position, the controllerdetermines whether an external load acts on the refrigerator door in adirection in which the refrigerator door is closed based on informationdetected from the motor rotation detecting portion, and when it isdetermined that the external load acts on the refrigerator door, themotor is rotated in the other direction so that the push rod returns tothe initial position.
 9. The refrigerator according to claim 8, whereinthe motor rotation detecting portion outputs a pulse in the rotationprocess of the motor, and in the case in which the number of pulsesoutput per unit time in the motor rotation detecting portion is equal toor less than the number of detected loads, the controller rotates themotor in the other direction so that the push rod returns to the initialposition.
 10. The refrigerator according to claim 1, further comprisinga motor rotation detecting portion for detecting the rotation of themotor, wherein the controller determines whether the external load actson the refrigerator door in the direction in which the refrigerator dooris closed based on the information detected from the motor rotationdetecting portion in a state in which the push rod reaches to the dooropening position, and when it is determined that the external load actson the refrigerator door before the certain time elapses, the controllerrotates the motor in the second direction so that the push rod returnsto the initial position.
 11. The refrigerator according to claim 1,further comprising a door opening detecting portion for detectingwhether the refrigerator door is opened at equal to or more than areference angle, wherein when the door opening detecting portion detectsthat the refrigerator door is opened at equal to or more than thereference angle before the push rod returns to the initial position, thecontroller controls the motor so that the push rod returns to theinitial position.